Doorknob assembly



July 2, 1957 J. F. MICHAEL DOORKNOB ASSEMBLY Filed May 17, 1954 JAMES E MICHAEL,

ATTORNEK United States Patent O and DOORKNOB ASSEMBLY James F. Michael, Lawndale, Calif., assignor to E. F. Brown Sales Co., Lawndale, Calif., a firm Application May 17, 1954,. Serial No. 430,044

1 Claim. or. 292-347 This invention relates to door knob assemblies and more particularly to such an assembly in which the knob body is formed of china or porcelain materials.

Door kno b assemblies having knobs formed of china and porcelain material have long been desired, but have not been available for the reason that difliculty has heretofore been experienced in rigidly securing knobs of such materials to spindle or sleeve elements mountable to latch mechanisms for operation of the mechanisms. China and porcelain materials are formed by firing at elevated temperatures and no successful means has been heretofore developed for interconnecting a knob body to the metallic mounting member or sleeve for the reason that the metal would melt or distort in the firing operation necessary to finish the knob body.

In the present invention the china or porcelain knob is formed as a hollow body and is completed through a conventional firing operation. The knob may thus be given any decorative effects possible today with other china or porcelain bodies. In carrying out the invention, the knob is formed with an opening into which is fitted a non-circular head element of suitable metal carried by a sleeve member which is to be interconnected into the latch mechanism :by the same means as are conventional door knob assemblies today. The door knob is formed internally with surfaces interlockingly engaged with the head element in one relative position of the assemblage. .T his position is maintained through ahardened cement so that the knob and mounting sleeve are mechanically as well as adhesively interconnected.

The cement is introduced into the knob in a plastic state after which the head element is inserted into the opening and the thus completed assembly held in such an attitude that the cement flows into and completely fills the space surrounding the head element interlockingly engaged with the adjacent walls of the opening in the knob, as well as partially filling the knob itself.

Once the cement has set and hardened the head element is in effect embedded within the knob body and the completed assembly is extremly rugged. The jointure between the knob and the sleeve element will readily take the forces induced into the jointure through operation of the latch mechanism by rotation of the knob, and the service life of the assembly is as long as that expected of metallic assemblies now in use.

Other features and advantages of the present invention will :be hereinafter apparent from the following description, particularly when taken in connection with the accompanying drawing, in which:

Figure 1 is a perspective view illustrating a portion of a door and a door knob assembly mounted on the door in operative relationship to the door;

Figure 2 is a sectional view of a door knob assembly as taken along the axis of the assembly and illustrates the construction and relationship of certain components in the assembly.

Figure 3 is a sectional view taken substantially on the 2,797,950 Patented July 2, 1957 ice line 33 of Figure 2 and illustrates the components shown in Figure 2 in further detail;

Figure 4 is a sectional view taken on the line 44 of Figure 3, the components being shown in exploded relationship for purposes of clarity;

Figure 5 is a fragmentary sectional view corresponding to that shown in Figure 2 and illustrating the knob in relation to the other components after it has been secured to the other components as by cement; and

Figure 6 is a side elevational View, partially broken away to indicate components in section of another embodiment of the invention.

The door knob assembly of the present invention, and particularly the embodiment shown in Figures 1 through 5, comprises a hollow knob body 10 and a sleeve member 11 which is to be telescopically fitted over a hollow spindle 12 of a latch mechanism of the type commonly termed a unit type latch set. As the latch mechanism forms no part of the present invention, only a fractional part of the hollow spindle 12 has been illustrated in the drawing. In the unit type of latch mechanism a detent mem ber 13 is carried within the hollow spindle 12 and is normally urged radially outward through a slot 14 by a leaf spring 15, one end of which is anchored to the inner wall of the hollow spindle.

The sleeve 11 is fixed to the spindle 12 by reception of the spring pressed detent 13 in one of a pair of diametrically spaced slots 16 formed, as clearly shown in Figure 2, in the wall of the sleeve 11. It will be understood that as the sleeve 11 is fitted over the hollow spindle 12 registration of one of the slots 16 with the slot 14 will permit the detent to move outwardly to be en gaged in the registering slot 16. This engagement in eifect keys the sleeve 11 to the hollow spindle 12 to the end that the spindle 12 is rotated by rotation of the sleeve 11. The pair of diametrically opposed slots 16, each clearly seen in Figure 2, permits interconnection of the knob assembly to the spindle 12 in the same relative attitude regardless of the side of the door to which the knob assembly is mounted.

The knob body 10 is formed as a hollow member from any suit-able china or porcelain material. This body, in the now preferred method of making up the assembly, is cast as two body halves and after the body halves have been joined to complete the knob, it is coated with some suitable glaze or vitreous material prior to the firing operation. The one body half is preformed with a non-circular opening 17 as best shown in Figure 3 of the drawing. In the illustrated embodiment the opening 17 has been shown as square although other non-circular openings can be used. The opening 17 is substantially the same size and shape as a head element 18 formed at the free end of a neck or shank member 19 integrally formed with and longitudinally projecting from a Wall portion 21 closing the one end of the sleeve 11.

In the actual practice of the invention the sleeve 11, the neck 19, and the head element 18 are machined from a solid bar of brass or other suitable material. The exposed face of the wall portion 21 is formed during this operation with an annular recess 22, the purpose of which will be hereinafter made clear and which circumscribes the root portion of the shank member 19.

The Wall portion of the knob body 10 immediately surrounding the opening 17 is preferably thickened and the defining edges of the opening on the inner side of the thickened wall portion, as best seen in Figure 3, areqflared outwardly at the corners defining the intersection of each pair of contiguous sides to form spaced recesses 23. The outwardly flared recesses present angularly extending surfaces or shoulders which face inwardly of the knob body as clearly shown in Figure 4 of the drawing. The head element 18 is also square in shape and is of a size relative to the size of the opening 17 as to be easily inserted axially into the opening. Once the head element is inserted into the opening and then rotated relative to the knob body 10, the corners or shoulders of the head element move against and interlockingly engage with the inwardly facing surfaces of the recess 23. So long as the shoulders formed by the corners of the head element 18 are interlockingly engaged with the undercut surfaces formed by the spaced recesses 23, the sleeve will be held against longitudinal movement in the direction necessary to withdraw the head 18 from the knob body.

To hold the knob and sleeve against relative rotation such as to move the head element out of engagement with the undercut surfaces of the recesses 23, a cementitious material inserted into the hollow knob body is used. In the operation of assembling the knob to the sleeve 11, the cementitious material 24 in a plastic state is poured into the hollow knob through the opening 17, after which the head 18 is inserted through the opening. The thus assembled knob and sleeve is then placed in the attitude shown in Figure of the drawing and the knob slightly separated from the sleeve to permit the still liquid cement 24 to flow downwardly through the recesses 23 and around the annular space between the neck 19 and the walls .of the opening 17 to substantially fill the recess 22 formed in the face of the wall portion 21. Once the cementitious material has substantially filled the recess, the knob and sleeve are rotated relative to each other to move the sharp corners of the head 18 into engagement with the undercut surf ces presented by the flared reces es 23. The knob is then allowed to remain in the attitude of Figure 5 until the cement has set and hardened. Once the cement has set and hardened, the knob is very rigidly attached to the sleeve not only through the interlocking engagement of the head 18 with the surfa es of the recesses 23, but also through the ad hesive acticn of the cement which, as should now be understood, also prevents relative rotation of the kn b nd head 18 "nd sleeve 11 to the position in which the head c uld be withdrawn from the opening 17.

It is now preferred to use a china cement. i. e., cement which will se urely bond china to china. This cement is preferably mixed with sufficient magnesium chloride to form a slurry which will flow as hereinbefore described. This cement expands slightly as it sets nd herdens so that it inherently acts to completely fill the speces formed by the contiguous surfaces of the head 18, neck 19, recess 22 and the walls of the opening 17.

The cement, after it has set and hardened, completely embeds the head 18 as well as the neck element 19 and thus acts to hold the head 18 from moving out of engagement with the surfaces of the recess 23. Sulficient cement is introduced into the knob at the initial assembly operation so that a substantial part of the knob is filled with the hardened cement. The cement practically forms an integral part of the knob body after it has set and hardened to the end that the head 18 is, therefore, in effect embedded within the knob body itself.

It will thus be seen that the thickened wall portion of the knob body, and not the cement, acts to prevent longitudinal movement of the sleeve in a direction tending to separate the sleeve from the knob. As the cement will rigidly hold the head element against rotation relative to the knob body, the sleeve, as should now be understood, is rigidly held against separation from the knob body. Substantially all torque loads induced into the assembly by rotation of the knob are taken by the metal head through engagement of the surfaces of the recesses 23 with the corners of the head. The cement, as it acts merely to embed the head and to prevent rotation thereof relative to the knob body, takes practically no stresses occurring through operation of the knob to actuate the latch mechanism.

In the embodiment of the present invention shown in Figure 6, a knob body identical in all respects to the knob body 10 is shown mounted to a mounting or sleeve element 30 of the type used to mount a knob to a latch mechanism having a threaded spindle 31. In this embodiment of the invention, the sleeve 30 is formed with a neck 32 carrying a head 33 identical to the head 18 of the embodiment of the invention earlier described. Here again the knob 10 is assembled with the mounting sleeve 30 through a cementitious material in exactly the same way as was the head 18 of the earlier described embodiment held within the knob body 10. In this embodiment of the invention the sleeve 30 is threaded onto the spindle 31 to some desired position after which a headless screw 34 is tightened against the spindle 31 to prevent relative rotation between the sleeve 3%) and the spindle 31.

Although the now preferred embodiments of the present invention have been shown and described herein, it is to be understood that the invention is not to be limited thereto, for it is susceptible to changes in form and detail within the scope of the appended claim.

I claim:

A door knob assembly comprising: a hollow knob of ceramic material forming a chamber with an axial entrance aperture into the chamber, the diameter of the chamber being the major portion of the diameter of the knob to provide a relatively large reservoir space for cementitious material whereby a liberal quantity of fluent cementitious material may be poured into said chamber and then the knob may be turned to a position to cause the cementitious material to gravitate into said entrance aperture; a hardened pool of cementitious material in said chamber positioned on the side of the chamber where said entrance aperture is located and reinforcing said side of the chamber; and a spindle mechanically interlocked with said knob and held by the hardened cementitious material against rotation out of mechanical engagement with the knob, said spindle having a reduced neck with a head thereon of rectangular crosssectional configuration formed with corners, said head being completely submerged in said hardened pool with the pool bonded to the end face of the head, said entrance aperture being of similar cross-sectional configuration with recesses at the corners of the aperture at the inner end of the aperture to form shoulders for mechanical engagement by the corners of said head, whereby, with a quantity of fluent cementitious material in said chamber, said head may be inserted into said aperture, said knob may then be placed in a position to cause the cementitious material to gravitate into said aperture, said spindle may then be rotated for mechanical engagement of said corners of the head with said recesses and then the cementitious material may be permitted to harden with the knob in said position, said spindle having an end wall at the base of said neck to cooperate with the adjacent portion of said knob to cut off said aperture to prevent drainage of the fluent cementitious material out of said chamber while the cementitious material is hardening with the knob in said position.

References Cited in the file of this patent UNITED STATES PATENTS 88,919 Sloan Apr. 30, 1869 196,852 Young Nov. 6, 1877 223,259 Tucker Jan. 6, 1880 1,621,174 Schlage Mar. 15, 1927 2,726,891 Gresham et a1 Dec. 13, 1955 

